Device for interrupting the fuel supply

Abstract

The invention relates to an internal combustion engine, in particular a one cylinder diesel engine, with a fuel injection system. The engine is provided with a mechanical control device comprising an actuator and a control element for automatic interruption of the fuel supply in case of a lack of lubricating oil. The control circuit actuator is equipped with a vacuum advance (15) with a membrane (12) for the pressurization of a closing tappet (10), in which a pressure chamber, formed by the membrane (12) and the vacuum advance (15), is open to the atmosphere. In addition, the control conduit (18) is equipped with a connection (20) on the side of the oil circuit and a connection (22) on the side of the crankcase, in order to produce a depression the control unit.

What is claimed is: 
     
       1. An internal combustion engine, in which a mechanical safety device is provided for automatic interruption of the fuel supply in the event of lubricating-oil deficiency wherein as the final controlling element of a control loop there is provided a reduced-pressure cell (15; 57) with a diaphragm (12; 58) for exerting pressure on a closing tappet (10; 60; 60), said reduced pressure cell (15; 57) being subdivided by the diaphragm, (12; 58) into a first pressure chamber (16; 71) open to the atmosphere and a second pressure chamber (19; 70) subjected to pneumatic reduced pressure and in that there are provided a control line means (18; 55; 56) with a connection (20) on the oil-loop side and a connection (22) on the crankcase side to generate a reduced pressure in said second pressure chamber (19) and a restoring spring (14; 59) acting on the diaphragm (12; 58) for automatic restoration on the fuel feed. 
     
     
       2. An internal combustion engine according to claim 1, wherein the fuel-injection system is provided with a fuel-injection pump (1; 63) with a suction hole (5; 64), the closing tappet (10; 60) being provided to close the suction hole (5; 64). 
     
     
       3. An internal combustion engine according to claim 1, wherein, the closing tappet (10; 60) is permanently joined to the diaphragm (12; 58). 
     
     
       4. An internal combustion engine according to claim 1, wherein, on the side facing away from the diaphragm (12), the restoring spring (14) acts on a pressure plate (7). 
     
     
       5. An internal combustion engine according to claim 1, wherein, the closing tappet (10; 60) is of self-centering construction. 
     
     
       6. An internal combustion engine according to claim 1, wherein, two throttles (21, 23; 72, 73) are provided in the control line, one downstream from the connection (20) on an oil-loop side and the other upstream from the connection (22) on a crankcase side, in order to make the line pressure independent of oil viscosity and delivery flow of the oil loop. 
     
     
       7. An internal combustion engine according to claim 1, wherein, a throttle (21) is provided in the control line (18) downstream from the connection (20) on an oil-loop side and a valve (35) is provided upstream from the connection (22) on a crankcase side. 
     
     
       8. An internal combustion engine according to claim 1, wherein, a line (17) in communication at one end with the reduced-pressure cell (15) is provided in the control element for evacuating and ventilating the pressure chamber (19), at its other end this line being in communication via a check valve (30) with the control line (18) and a ventilation throttle (26) with the atmosphere. 
     
     
       9. An internal combustion engine, according to claim 1, wherein there is provided a first control line (55) with a connection on an oil-loop side and a second control line (56) with a connection on a crankcase side in the control element. 
     
     
       10. An internal combustion engine according to claim 9, wherein, there is provided an evacuation device for manual evacuation of the side which is connected to the atmosphere of the diaphragm (58). 
     
     
       11. An internal combustion engine according to claim 10, wherein, as the evacuation device there is provided a check valve (67), a rubber bellows (65) with a compression spring (66), a ventilation throttle (69) and an evacuation line (68).